Apparatus for continuously sharpening a rotary blade

ABSTRACT

Apparatus for guarding and continuously sharpening a rotary cutting blade of the type used with tire truing apparatus. The blade sharpening apparatus includes a rotary grind wheel which is positioned on one side of the blade for continuous sharpening engagement with the cutting edge. The grind wheel is adjustably mounted relative to the blade, and may be resiliently biased into contact therewith. A deburring member engages the other side of the cutting edge, and the deburring member is mounted for effective deburring action irrespective to the direction in which the blade rotates. The blade guard includes a member which normally surrounds a selected portion of the sharp periphery of the blade and which is selectively retractable to expose the blade for cutting purposes.

Rees

Mar. 4, 1975 APPARATUS FOR CONTINUOUSLY SHARPENING A ROTARY BLADE [76]Inventor: J. Samuel Rees, Rt. 1, Box 4,

Preston, Ga. 31824 [22] Filed: Sept. 25, 1972 [21] Appl. No.: 291,734

[52] [1.8. CI. 51/248, 83/1741 [51] Int. Cl. B24b 3/36 [58] Field ofSearch 51/246, 247, 248, 250; 83/174, 174.1

[56] References Cited I v UNITED STATES PATENTS 1,176,136 3/1916 Demuth51/248 1,772.704 8/1930 Campbell 1.939.754 12/1933 Woodington 2,052,3658/1936 Stukart 51/248 Primary E.\-aminer-Al Lawrence: Smith AssistantExaminer-Nicholas P. Godici Attorney, Agent, or F irm-Jones, Thomas &Askew [57] ABSTRACT Apparatus for guarding and continuously sharpening arotary cutting blade of the type used with tire truing apparatus. Theblade sharpening apparatus includes a rotary grind wheel which ispositioned on one side of the blade for continuous sharpening engagementwith e ti g ed e Th. l 51 whee s edi saw tnqunte relative to the blade,and may be resiliently biased into contact therewith. A deburring memberengages the other side of the cutting edge, and the deburring mem her ismounted for effective deburring action irrespective to the direction inwhich the blade rotates. The blade guard includes a member whichnormally surrounds a selected portion of the sharp periphery of theblade and which is selectively retractable to expose the blade forcutting purposes.

9 Claims, 6 Drawing Figures PATENTEDMAR 4197s SHEET 2 If 2 I APPARATUSFOR CONTINUOUSLY SHARPENING A ROTARY BLADE This invention relates ingeneral to apparatus for use with a rotary cutting blade and inparticular to apparatus for guarding and continuously sharpening arotary cutting blade of the type used in tire truing apparatus, forexample.

The increasing cost of automotive tires, coupled with the increasingpopularity of relatively expensive types of tires suchas belted tiresand radial tires, has made tire users acutely aware of the need tomaximize the usable tread life of their tires. One of the known ways inwhich tire tread life can be optimized involves a technique commonlyreferred to as truing a tire, which utilizes special apparatusfunctioning in the nature of a lathe to remove rubber from the peripheryof the tire tread as necessary to make the tire truly round with respectto the center of rotation of the tire as mounted on a wheel. Tire truingapparatus generally utilizes a rotary blade having a sharp peripheraledge which is traversed along the width of the tire tread while the tireis rotated relative to the spinning rotary blade. In actual practice,the turing operation is carried out in two separate phases, with onehalf of the tread width being trued while the rotary blade is spinningin a first direction and with the other half of the tire tread widthbeing trued while the blade is spinning in the opposite direction.

It is apparent that the rotary tire truing blade must have anexceedingly sharp edge if the tire truing operation is to be performedexpeditiously and with the removal of only the amount of tread rubbernecessary to achieve a truly round condition. Moreover, it is essentialthat the blade remain sharp throughout a tire truing operation.

It is apparent that any blade sharpening device which requires removalof the blade from the truing apparatus, or which at least interfereswith the tire truing operation during the sharpening process, iswasteful of time and effort on the part of the truing machine operator,and is also wasteful of truing machine time which could be profitablyspent in truing tires.

Another aspect of maintaining a sharp peripheral edge on a rotary tiretruing blade involves protecting the blade edge from damage resultingfrom unwanted contact with foreign objects. For example, it is possibleto bump the blade with a tire while the tire is being mounted on thetruing machine, and this contact with the blade can cause blade damageand can also cause cutting damage to the tire. Furthermore, the presenceof an exposed sharp blade edge in the crowded environment frequentlyassociated with tire-changing shops is conducive of injury to the peoplewho work around the truing machines.

Accordingly, it is an object of the present invention to provide animproved apparatus for sharpening the blade of a tire truing machine.

It is another object of the present invention to provide improvedapparatus for guarding the blade of a tire truing machine.

It is still another object of the present invention to provide improvedcutting apparatus including apparatus for sharpening and for guardingthe blade of a tire truing machine.

It is a further object of the present invention to provide apparatus forcontinuously sharpening the blade of a tire truing machine.

Many of the other objects and attendant advantages of the presentinvention will become more readily apparent from the followingdescription of a disclosed, preferred embodiment thereof, including thedrawing in which:

FIG. I shows an isometric view of the cutting blade portion of a tiretruing apparatus, including blade sharpening apparatus according to thedisclosed embodiment of the present invention;

FIG. 2 shows a section view taken along line 2-2 of FIG. 1;

FIG. 3 shows an end elevation view of the blade sharpening apparatus ofFIG. 1 with the blade removed;

FIG. 4 shows a side elevation view of the apparatus shown in FIG. 3;

FIG. 5 shows an isometric view of the blade cutting portion of a tiretruing apparatus, including a blade guard'according to the disclosedembodiment of the present invention; and

FIG. 6 shows the blade guard of FIG. 5, in retracted position, mountedin combination with the blade sharpening apparatus of FIG. 1.

Stated in general terms, the present invention includes a rotary grindwheel disposed in contact with one side of the peripheral edge of ablade to be sharpened, and further includes a deburring member disposedagainst the other side of the rotary blade. The grind wheel is permittedto rotate as the cutting wheel rotates. The deburring member is mountedfor a limited extent of motion determined by the rotational direction ofthe cutting wheel, so that an appropriate contact angle between thedeburring member and the cutting wheel is maintained irrespective of thedirection in which the cutting wheel rotates. The blade guide ispositionable in a first position disposed in surrounding, spaced-apartrelation with at least a portion of the periphery of the blade edge, andis selectively retractable to a position exposing the blade for cutting.The blade guard is readily adaptable to be mounted on a conventionalmotor of a tire truing apparatus with little or no modificationrequired.

Stated more particularly, the particular disclosed embodiment of thepresent invention shows a tire tread cutting apparatus indicatedgenerally at 10 and including a rotary cutting blade 11 having a sharpperipheral cutting edge 12 extending around the entire circumfer ence ofthe blade. The blade 11 is mounted for rotation on the shaft 13 of asuitable power source such as the motor 14, and the motor is attached bya suitable mount (not shown) placing the blade in cutting relation witha tire to be trued. Additional details of tire truing apparatus areknown to the art and are, accordingly, omitted from the description ofthe disclosed embodiment of the present invention.

The blade guard apparatus of the disclosed embodi ment, as shown inFIGS. 5 and 6, includes an edge surrounding member 21 which in thedisclosed embodiment takes the shape of a semicircular member concentricwith the rotary cutting blade 11 and which is disposed a spaced distancefrom the circumferential cutting edge 12 of the blade. The edgesurrounding member 21 includes a wall portion 22 extending inwardlytherefrom. Although the circumferential extent of the edge surroundingmember 21 is approximately in the shape of a semicircle in the disclosedembodiment, it will be understood that this is not by way of limitation;it is generally preferable that the edge surrounding member 21 cover atleast that portion of the cutting edge which is most exposed to damageby unwanted contact with the blade, however.

Attached to'the edge surrounding member 21 are a support member 23 and aguide member 24. Both the support member 23 and the guide member 24extend outwardly from the edge surrounding member 21 in angular relationto the motor shaft 13 to a point at a location approximately greaterthan the external dimension of the motor 14, whereupon the supportmember and the guide member extend in substantially parallel relationwith each other along the exterior of the motor. The support member 23,for example, includes a rod 25 which is slidably received within thetube 26, which may be secured to the motor 14 by any suitable attachmentsuch as the tabs 27 and 28. A knob 29 is attached to the end of the rod25 extending outwardly of the tube 26. The guide member 24 includes arod portion 30 which may be substantially parallel with the rod 25 andwhich is disposed to rest along the side of the motor 14 opposite to thetube 26 for sliding movement.

Frictional force between the rod 25 and the tube 26, and between the rodportion 30 and the motor, is generally sufficient to retain the bladeguard apparatus in a retracted position, although it will be understoodthat a suitable catch mechanism may alternatively be used for thepurpose.

In considering the operation of the herein-described blade guard, it isinitially assumed that the guard is in the position shown in FIG. withthe edge surrounding member 21 disposed in peripheral, spaced-apartrelation with the cutting edge 12 of the blade. It can be seen that anyobject, such as a tire or a dropped tool, which approaches the blade 11on an approach path extending from directly above thecutting edge toapproximately a horizontal plane with the cutting edge, will contact thesurrounding member 21 instead of the cutting edge 12. The coextensivewall portion 22 adds great structural strength to the edge surroundingmember 21 and prevents this member from becoming deformed or otherwisedamaged by striking impacts. It will also be seen from the followingdescription of the blade sharpening apparatus that the blade 11 can berotated to sharpen the edge 12 while the blade guard is disposed insurrounding relation as shown in FIG. 6. When it is desired to withdrawthe guard and expose the blade for use, the knob 29 is simply pulled ina direction away from the motor 14, as indicated by the arrow in FIG. 1,whereupon the rod 25 and the support member 23 retract the edgesurrounding member 21 to a location whereat the cutting edge of theblade is fully exposed. The rod 30 attached to the guide member 24defines the movement of the edge surrounding member 21 so that thismember will not contact or otherwise interfere with the operation of thecutting blade 11.

Turning next to a consideration of the disclosed embodiment of the bladesharpening portion of the present invention, a mounting block 40 havingan opening 41 of diameter larger than the motor shaft 13 is suitablyattached to the front end 42 of the motor 14. A pair of guide members 43and 44 are slidably disposed in corresponding passageways extendingthrough the mounting block 40 on either side of the opening 41, and thetwo guide members 43 and 44 are secured at first ends thereof to asupport block 45. The opposite ends of the guide members 43 and 44 aresecured in a retaining member 46. The retaining member 46 is biased awayfrom the mounting block by suitable resilient devices such as thecompression springs 47 and 48 which surround the ends of the guidemembers 43 and 44 extending between the retaining member and themounting block. A threaded rod 49 is secured in the mounting block 40and extends outwardly to pass freely through an opening in the retainingmember 46. A knob 51 is threaded onto the free end of the threaded rod49.

Extending from the support block in a direction toward the cutting blade11 is an arm 56 which may be substantially parallel with the motor shaft13 and which has a free end 57 positioned on the side of the cuttingblade 11 remote from the motor 14. A circular grind wheel 58 is mountedas at 59 for rotation on the free end 57. It is particularly apparentfrom FIG. 3 that the free end 57 has a predetermined angular relationrelative to the arm 56 which places the side 60 of the grind wheel 58into the desired contact with one beveled side 61 of the cutting blade11. It will be understood that the specific angular orientation of thefree end 57 is thus determined by the particular cutting blade and theparticular side configuration of the grind wheel in use, as is obviousto those skilled in the art of blade sharpenmg.

It has been found that the dimensions of the free end 57 and the arm 56are preferably chosen to minimize the clearance space 64 which existsbetween the lowermost point on the grind wheel 58 and the arm 56. In theillustrated embodiment, the support arm 56 has been undercut as at 65 toprovide the aforementioned minimum clearance 64. It has been found thatthe accumulation of rubber particles which would otherwise occur aroundthe grind wheel and associated mounting components is minimized if noteliminated by maintaining the clearance space 64 at substantially thatminimum amount required to permit unimpeded rotation of the grind wheelat all times.

A deburring tool 68 having an edge 69 disposed for engagement with thecutting edge 12 of the blade 11 is mounted on a post 70 received forsliding and reciprocal movement within a hollow tube 71 secured to themounting block 40 and terminating a spaced distance from themotor-confronting side of the cutting blade. A pin 72 secured to thepost 70 and extending through an elongated slot 73 in the tube 71provides a lostmotion connection between the tube and the post, with thewidth of the slot 73 being sufficiently larger than the diameter of thepin 71 to permit a limited extent of angular movement of the post 70relative to the tube 71. The post 70 is biased outwardly by means of aspring (not shown) enclosed within the tube 71 to place the edge 69 intocontact with the cutting blade 11.

Continuous sharpening of the cutting blade 11 is accomplished byadjusting the knob 51 to permit the support block 45 to be drawn towardthe mounting block 40 to an extent which places the side 60 of the grindwheel 58 into grinding engagement with the beveled side 61 ofthe cuttingblade 11. The knob 51 may be adjusted an amount beyond the point ofadjustment whereat the grind wheel and the cutting blade begin to makecontact, so that resilient contact between the grind wheel and thecutting blade is maintained by the force of the springs 47 and 48. Thisresilient biased contact of the grind wheel 58 against the rotarycutting blade 11 allows the abrasive side 60 to maintain constantcontact with the beveled side 61 throughout rotation of the cuttingblade irrespective of any eccentric movement caused by the cutting bladebeing out of round, It will be understood that rotational movement isimparted to the grind wheel 58 by rotation of the cutting blade 11.

Since the grind wheel always contacts only one side of the cuttingwheel, it is necessary to maintain the edge 69 of the deburring tool 68in constant contact with the other side of the cutting blade to maintaina smooth and burr-free cutting edge 11. Moreover, since the cuttingblade 11 is rotated in opposite directions during a tire truingoperation, the lost-motion mounting of the deburring tool provided bythe pin 72 movably received within the slot 73 enables the edge 69 toassume an appropriate following angle of contact with the cutting blade11.

It will be understood that the foregoing relates only to a preferreddisclosed embodiment of the present invention, and that numerousalterations and modifications may be made therein without departing fromthe spirit or the scope of the invention as set forth in the ap pendedclaims.

What is claimed is:

1. Apparatus for continuously sharpening the peripheral edge of a rotarycutting blade, comprising:

a blade sharpening member mounted in blade sharpening contact with oneside of the peripheral edge of a blade to be sharpened;

deburring means mounted to be disposed in operative contact with theother side of said peripheral edge;

said deburring means including a deburring member urged into contactwith such other side at a predetermined certain contact angle followingthe peripheral movement of the blade edge in a first direction ofrotation; and

means disposing said deburring member for limited angular movementrelative to the peripheral edge of the blade to permit said deburringmember to assume said predetermined certain contact angle in response toselective rotation of said rotary cutting blade in either direction.

2. Apparatus as in claim 1, further comprising:

adjustable means supporting said blade sharpening member for selectivelyadjusting the position of said blade sharpening member relative to thecutting blade without changing the position of said deburring memberrelative to the cutting blade.

3. Apparatus for continuously sharpening the peripheral edge of a rotarycutting blade, comprising:

a blade sharpening member mounted in blade sharp ening contact with oneside of the peripheral edge of a blade to be sharpened;

deburring means mounted to be disposed in operative contact with theother side of said peripheral edge;

a mounting member secured in fixed spaced relation to the rotary cuttingblade;

a support member connected to said mounting member in spaced relationwhich is selectively adjustable along a predetermined path of movement;

first means connected to said support member and mounting said bladesharpening member in proximate relation to said one side of theperipheral edge of the rotary cutting blade so that sharpening contactbetween said blade sharpening member and the peripheral edge is obtainedby said selective adjustment;

second means connected to said mounting member in spaced relation withsaid other side of the peripheral edge;

said deburring means supported by said second means for said dispositionin operative contact with the other side of the peripheral edge; and

connecting means interposed between said second means and said deburringmeans and operative to allow said deburring means to undergo apredetermined limited extent of movement defining a certain angle ofcontact between said rotary cutting blade and said deburring means inresponse to rotation of said peripheral edge in either direction.

4. Apparatus as in claim 3, wherein:

said connecting means comprises an aperture in one of said second meansand saidl deburring means and having a certain dimension in alignmentcorresponding to said direction of deburring means limited movement;

a lug dimensioned to be movably received in said aperture and connectedto the other of said second means and said deburring means, said lugdisposed in said aperture for movement along said certain dimensionthereof to allow said deburring means to undergo said movement.

5. Apparatus for continuously sharpening the peripheral edge of a rotarycutting blade, comprising:

a blade sharpening member mounted in blade sharpening contact with oneside of the peripheral edge of a blade to be sharpened;

deburring means mounted to be disposed in operative 'contact with theother side of said peripheral edge;

a mounting member secured in fixed spaced relation to the rotary cuttingblade;

a support member connected to said mounting member in spaced relationwhich is selectively adjust able along a predetermined path of movement;

first means connected to said support member and mounting said bladesharpening member in proximate relation to said one side of theperipheral edge of the rotary cutting blade so that sharpening contactbetween said blade sharpening member and the peripheral edge is obtainedby said selective adjustment;

second means connected to said mounting member in spaced relation withsaid other side of the peripheral edge;

said deburring means supported by said second means for said dispositionin operative contact with the other side of the peripheral edge;

said cutter blade being mounted for rotation on a shaft extendingoutwardly of a drive means;

said mounting means being secured in fixed relation relative to saiddrive means and said cutter blade;

adjustable means connecting said support member to said mounting memberfor providing a selectively adjustable amount of spacing along adirection radial to the shaft of said drive means;

said adjustable connecting means including resilient means urging saidsupport member toward said selected amount of spacing and resilientlyyieldable in a direction of increased spacing from said shaft;

said first means extending from a first end at said support member inspaced relation to said shaft and the peripheral edge of the cuttingblade to terminate at a second end adjacent said one side of theperipheral edge of the cutting blade;

said blade sharpening means comprising a grind wheel mounted forrotation on said second end of said first means at an angle placing anabrasive surface of said grind wheel in rotation-imparting contact withsaid peripheral surface;

said second means comprises a member defining a receptacle facing towardsaid other side of said peripheral edge; and

said deburring means includes a member received in said receptacle andoperative to undergo no more than a limited extent of movement indirections corresponding to the directions of rotation of saidperipheral edge.

6. Apparatus for continuously sharpening the peripheral edge of a rotaryblade mounted for rotation by a drive shaft, comprising:

a support member mounted in fixed relation to the peripheral edge of therotary blade;

first support means adjustably connected to said support member forselective positioning in radial spaced apart relation to said peripheraledge;

said first support means including resilient means urging said firstsupport means toward said selected radially spaced position and beingresiliently yieldable in a direction of increased radial spacing;

a blade sharpening member mounted on said first support means maintainedin blade sharpening contact with one side of said peripheral edge; and

deburring means mounted on said support member and urged into maintaineddeburring contact with another side of said peripheral edge,irrespective of said radial spacing of said blade sharpening member onsaid first support means.

7. Apparatus as in claim 6, wherein said deburring means comprisessecond support means extending from said support member and maintainingsaid deburring means in predetermined angle of deburring contact withsaid other side of the peripheral edge irrespective of the direction inwhich said blade rotates.

8. Apparatus as in claim 6, wherein:

said first support means extends from said support member at a locationspaced from said other side of the peripheral edge of the cutting bladeto an end spaced from said one side thereof; and

said blade sharpening member comprises a grind wheel mounted forrotation on said end of said first support means and having an abrasivesurface yieldingly maintained in engagement with said one side of theperipheral edge.

9. Apparatus as in claim 8, wherein:

said end of said first support includes an angularly disposed memberdefining a location whereat said grind wheel is mounted for rotation;

said location on said angularly disposed member extending from said endof first support means no more than the minimum extent necessary toprovide rotational clearance between said grind wheel

1. Apparatus for continuously sharpening the peripheral edge of a rotarycutting blade, comprising: a blade sharpening member mounted in bladesharpening contact with one side of the peripheral edge of a blade to besharpened; deburring means mounted to be disposed in operative contactwith the other side of said peripheral edge; said deburring meansincluding a deburring member urged into contact with such other side ata predetermined certain contact angle following the peripheral movementof the blade edge in a first direction of rotation; and means disposingsaid deburring member for limited angular movement relative to theperipheral edge of the blade to permit said deburring member to assumesaid predetermined certain contact angle in response to selectiverotation of said rotary cutting blade in either direction.
 2. Apparatusas in claim 1, further comprising: adjustable means supporting saidblade sharpening member for selectively adjusting the position of saidblade sharpening member relative to the cutting blade without changingthe position of said deburring member relative to the cutting blade. 3.Apparatus for continuously sharpening the peripheral edge of a rotarycutting blade, comprising: a blade sharpening member mounted in bladesharpening contact with one side of the peripheral edge of a blade to besharpened; deburring means mounted to be disposed in operative contactwith the other side of said peripheral edge; a mounting member securedin fixed spaced relation to the rotary cutting blade; a support memberconnected to said mounting member in spaced relation which isselectively adjustable along a predetermined path of movement; firstmeans connected to said support member and mounting said bladesharpening member in proximate relation to said one side of theperipheral edge of the rotary cutting blade so that sharpening contactbetween said blade sharpening member and the peripheral edge is obtainedby said selective adjustment; second means connected to said mountingmember in spaced relation with said other side of the peripheral edge;said deburring means supported by said second means for said dispositionin operative contact with the other side of the peripheral edge; andconnecting means interposed between said second means and said deburringmeans and operative to allow said deburring means to undergo apredetermined limited extent of movement defining a certain angle ofcontact between said rotary cutting blade and said deburring means inresponse to rotation of said peripheral edge in either direction. 4.Apparatus as in claim 3, wherein: said connecting means comprises anaperture in one of said second means and said deburring means and havinga certain dimension in alignment corresponding to said direction ofdeburring means limited movement; a lug dimensioned to be movablyreceived in said aperture and connected to the other of said secondmeans and said deburring means, said lug disposed in said aperture formovement along said certain dimension thereof to allow said deburringmeans to undergo said movement.
 5. Apparatus for continuously sharpeningthe peripheral edge of a rotary cutting blade, comprising: a bladesharpening member mounted in blade sharpening contact with one side ofthe peripheral edge of a blade to be sharpened; deburring means mountedto be disposed in operative contact with the other side of saidperipheral edge; a mounting member secured in fixed spaced relation tothe rotary cutting blade; a support member connected to said mountingmember in spaced relation which is selectively adjustable along apredetermined path of movement; first means connected to said supportmember and mounting said blade sharpening member in proximate relationto said one side of the peripheral edge of the rotary cutting blade sothat sharpening contact between said blade sharpening member aNd theperipheral edge is obtained by said selective adjustment; second meansconnected to said mounting member in spaced relation with said otherside of the peripheral edge; said deburring means supported by saidsecond means for said disposition in operative contact with the otherside of the peripheral edge; said cutter blade being mounted forrotation on a shaft extending outwardly of a drive means; said mountingmeans being secured in fixed relation relative to said drive means andsaid cutter blade; adjustable means connecting said support member tosaid mounting member for providing a selectively adjustable amount ofspacing along a direction radial to the shaft of said drive means; saidadjustable connecting means including resilient means urging saidsupport member toward said selected amount of spacing and resilientlyyieldable in a direction of increased spacing from said shaft; saidfirst means extending from a first end at said support member in spacedrelation to said shaft and the peripheral edge of the cutting blade toterminate at a second end adjacent said one side of the peripheral edgeof the cutting blade; said blade sharpening means comprising a grindwheel mounted for rotation on said second end of said first means at anangle placing an abrasive surface of said grind wheel inrotation-imparting contact with said peripheral surface; said secondmeans comprises a member defining a receptacle facing toward said otherside of said peripheral edge; and said deburring means includes a memberreceived in said receptacle and operative to undergo no more than alimited extent of movement in directions corresponding to the directionsof rotation of said peripheral edge.
 6. Apparatus for continuouslysharpening the peripheral edge of a rotary blade mounted for rotation bya drive shaft, comprising: a support member mounted in fixed relation tothe peripheral edge of the rotary blade; first support means adjustablyconnected to said support member for selective positioning in radialspaced apart relation to said peripheral edge; said first support meansincluding resilient means urging said first support means toward saidselected radially spaced position and being resiliently yieldable in adirection of increased radial spacing; a blade sharpening member mountedon said first support means maintained in blade sharpening contact withone side of said peripheral edge; and deburring means mounted on saidsupport member and urged into maintained deburring contact with anotherside of said peripheral edge, irrespective of said radial spacing ofsaid blade sharpening member on said first support means.
 7. Apparatusas in claim 6, wherein said deburring means comprises second supportmeans extending from said support member and maintaining said deburringmeans in predetermined angle of deburring contact with said other sideof the peripheral edge irrespective of the direction in which said bladerotates.
 8. Apparatus as in claim 6, wherein: said first support meansextends from said support member at a location spaced from said otherside of the peripheral edge of the cutting blade to an end spaced fromsaid one side thereof; and said blade sharpening member comprises agrind wheel mounted for rotation on said end of said first support meansand having an abrasive surface yieldingly maintained in engagement withsaid one side of the peripheral edge.
 9. Apparatus as in claim 8,wherein: said end of said first support includes an angularly disposedmember defining a location whereat said grind wheel is mounted forrotation; said location on said angularly disposed member extending fromsaid end of first support means no more than the minimum extentnecessary to provide rotational clearance between said grind wheel andsaid first support means.